Every NFL head coach pays lip service to running the ball, but when Matt LaFleur says it’s a priority, we might actually take him at his word.

The new Green Bay Packers coach comes from an offensive system, the Kyle Shanahan scheme, that revolves around the success of one run: the outside zone.

It’s the starting point of the Shanahan-Sean McVay offense, and for the first two days of training camp, it’s the only run Shanahan works on. We can expect the same at LaFleur’s first camp with the Packers this summer as he installs a scheme with the goal of getting Aaron Rodgers playing like an MVP again.

Packers running back Aaron Jones (33) is a good zone runner, but he has sustained three MCL tears in his two NFL seasons.(Photo: Jim Matthews/USA TODAY NETWORK-Wis)

“(The outside zone) basically sets up everything,” said Adam Stenavich, LaFleur’s offensive line coach and a Shanahan assistant with the San Francisco 49ers the last two years. “All the different blocking combinations and schemes, everything is tied into it. If you can make that go, then everything else opens up off of it.”

LaFleur’s offense goes directly back to the Mike Shanahan-Alex Gibbs scheme of the 1990s. Mike Shanahan, Kyle’s father, married the West Coast offense with Gibbs’ zone-blocking scheme and won two Super Bowls with an aging John Elway at quarterback. In Elway’s four seasons in the scheme, the Broncos finished in the top five in rushing every year and top five in scoring three times.

NFL offenses have evolved since, but Kyle Shanahan has kept the flame alive by building his more passing-oriented offense around the same outside zone run. He ran the scheme as his dad’s offensive coordinator in Washington from 2010 through 2013, then as Atlanta’s offensive coordinator in 2015 and ’16, and since then as the 49ers’ coach.

In Washington and Atlanta, LaFleur was one of his assistants.

McVay, likewise, runs the same scheme with the Los Angeles Rams, though with an important difference, which we’ll get to later. And LaFleur ran it last year as the Tennessee Titans’ offensive coordinator.

Without getting too lost in the weeds, we should start with a quick primer on the zone running scheme, which has two basic runs: inside zone and outside zone.

On both, offensive linemen come off the snap in unison like a chorus line, to the right or left, and are responsible for blocking an area.

On the inside zone, the ball carrier’s landmark is usually the gap between the guard and tackle. He either has to hit that gap or cut back to the biggest open lane. When you’ve seen Packers running back Aaron Jones take a handoff and hit a big run by cutting to the backside after only a step or two, it probably was an inside zone.

The outside zone is slower developing, because the back’s aiming point is usually the outside leg of the tight end. The runner has to be patient until he gets to that width, then decide whether try to make the corner or plant his foot and hit the nearest gap up field.

The reason the outside zone meshes with the passing game, at least when it’s working, is that it’s a slow-developing run. The line moves laterally in unison while the quarterback takes a longer path to the handoff with the ball extended for the defense to see. That holds the play-action fake an extra tick or two, which gives receivers more time to create separation and get downfield.

“It’s harder on the defense,” said an assistant coach from one of the 49ers’ rivals in the NFC West. “It forces the secondary to start their run-support roles faster than if it’s just a downhill run inside. That’s probably one of the biggest things people like about the outside zone.”

But for play action and bootlegs to work, the outside-zone run has to work. That takes a lot of practice time — “It’s not the easiest thing in the world to teach, (because) the running back and the offensive line have to be on the same page,” the assistant coach said — but also talent at running back.

This scheme, in fact, has produced the NFL’s leading-scoring team the last three years, and it’s no coincidence that the quarterback for each of those teams has thrived because of the quality he’s had at running back.

When Atlanta’s Matt Ryan won the NFL MVP award and led the league’s highest-scoring team in ’16, he had two good backs in Devonta Freeman and Devin Coleman. LaFleur was the Falcons’ quarterbacks coach that year.

The last two seasons, McVay’s Rams have led the league in scoring, and their best player has been running back Todd Gurley. As he melted down because of a knee injury late last season, so did quarterback Jared Goff.

LaFleur inherits a good zone runner in Jones, but he’s going to need another quality back to ensure he can make life easier for Rodgers. Jones has sustained three MCL tears in his two NFL seasons, and the Packers just can’t count on him to carry a heavy load or even finish out the year.

They need a second quality back if they’re going to run the ball the way LaFleur’s offense demands. While Jamaal Williams is the kind of tough, smart player you want on your team, he’s not that guy.

That’s why pursuing free agent Le’Veon Bell makes sense, depending on the price. If Bell’s market is a little soft, his combination of running and receiving skills would make him worth $12 million or $13 million a year in this offense.

A cheaper alternative could be Coleman, who turns 26 in April and will be a free agent in March. He rushed for 800 yards and a 4.8-yard average as the starter for the injured Freeman last season and has caught 90 passes the last three seasons. LaFleur knows him well from his time with the Falcons.

But if general manager Brian Gutekunst doesn’t sign a back in free agency, he’ll have to select one in this year’s draft, maybe even with a high pick.

What we don’t know is whether LaFleur’s version of the scheme will mirror Shanahan’s by making the fullback a big part of the offense, or if it will be more like the one used by McVay, who didn’t have a fullback on his roster last year.

Without a fullback, McVay predominantly plays three receivers and tries to spread the field horizontally. He liberally uses handoffs (and fakes) to receivers on jet sweeps to keep the defense spread out.

Shanahan’s alignment is more compact because he uses two backs more than anyone in the league. His fullback, Kyle Juszczyk, played 62.7 percent of the 49ers’ offensive snaps, almost double the next-highest fullback on the list, New England’s James Develin (35.6 percent).

“I personally believe the more you spread people out the harder it gets for them,” said the assistant from the NFC West.

The Packers have one fullback on their roster, Dany Vitale, who played 19 snaps from scrimmage after they signed him in December. He caught 135 passes in four years at Northwestern, so if LaFleur likes his blocking, Vitale could end up playing a lot this season.

But whichever way LaFleur goes, we know this: He and Rodgers have a lot riding on the outside zone.